<?php
/**
 * Created by PhpStorm.
 * User: Administrator
 * Date: 2016/9/28 0028
 * Time: 下午 8:09
 */
    header('Content-type:text/html:charset=utf-8');
    $name = '小明';
    $score = 78;
    if(is_int($score) || is_float($score)){
        if($score >=90 && $score <=100){
            $str = 'A级';
        }elseif($score >=80 && $score <90){
            $str = 'B级';
        }elseif($score >=70 && $score <80) {
            $str = 'C级';
        }elseif($score >=60 && $score <70) {
            $str = 'D级';
        }elseif($score >=0 && $score <60) {
            $str = 'E级';
        }else{
            $str = '学生成绩范围必须在0~100！';
        }
    }else{
        $str = '输入的学生成绩不是数值';
    }
